Methods of forming a colored conductive ribbon for integration in a solar module

ABSTRACT

The present disclosure describes methods of forming a colored conductive ribbon for a solar module which includes combining a conductive ribbon with a channeled ribbon holder, applying a color coating to at least the conductive ribbon within the channel, curing the color coating on the conductive ribbon, and separating the conductive ribbon from the channeled holder.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of and claims priority to U.S.application Ser. No. 16/411,002 filed May 13, 2019, which claimspriority to CN Patent Application No. 201811140595.5 filed Oct. 31,2018, which are hereby incorporated by reference in their entirety

TECHNICAL FIELD

The present disclosure relates to solar modules, and more particularly,to solar modules including improved efficiency and aesthetics byincluding colored electrically conductive ribbons, or other materialsthat can be attached directly to the solar cells and/or solar modules,which can be formed from the methods described herein.

BACKGROUND

Over the past few years, the use of fossil fuels as an energy source hasbeen trending downward. Many factors have contributed to this trend. Forexample, it has long been recognized that the use of fossil fuel-basedenergy options, such as oil, coal, and natural gas, produces gases andpollution that may not be easily removed from the atmosphere.Additionally, as more fossil fuel-based energy is consumed, morepollution is discharged into the atmosphere causing harmful effects onlife close by. Despite these effects, fossil-fuel based energy optionsare still being depleted at a rapid pace and, as a result, the costs ofsome of these fossil fuel resources, such as oil, have risen. Further,as many of the fossil fuel reserves are located in politically unstableareas, the supply and costs of fossil fuels have been unpredictable.

Due in part to the many challenges presented by these traditional energysources, the demand for alternative, clean energy sources has increaseddramatically. To further encourage solar energy and other clean energyusage, some governments have provided incentives, in the form ofmonetary rebates or tax relief, to consumers willing to switch fromtraditional energy sources to clean energy sources. In other instances,consumers have found that the long-term savings benefits of changing toclean energy sources have outweighed the relatively high upfront cost ofimplementing clean energy sources.

One form of clean energy, solar energy, has risen in popularity over thepast few years. Advancements in semiconductor technology have allowedthe designs of solar modules and solar panels to be more efficient andcapable of greater output. Further, the materials for manufacturingsolar modules and solar panels have become relatively inexpensive, whichhas contributed to the decrease in costs of solar energy. As solarenergy has increasingly become an affordable clean energy option forindividual consumers, solar module and panel manufacturers have madeavailable products with aesthetic and utilitarian appeal forimplementation on residential structures. As a result of these benefits,solar energy has gained widespread global popularity.

SUMMARY

The present disclosure provides solar modules and/or solar cellsincluding electrically conductive ribbons which are color-coated on atleast one side. In addition, methods of manufacturing such color-coatedelectrically conductive ribbons, or other materials that ma attacheddirectly thereto, are also provided.

In embodiments, methods of forming a colored conductive ribbon for asolar module are provided which include the steps of: a) providing aribbon holder including a channel configured to receive a conductiveribbon therein, b) securing the conductive ribbon in the channel of theribbon holder, c) applying a color coating to at least the conductiveribbon secured within the channel, d) curing the color coating on theconductive ribbon, and e) separating the conductive ribbon from thechannel of the ribbon holder.

In embodiments, the color coating may be a black composition or paint.

In embodiments, the color coating may be thermally insulative orelectrically conductive.

In embodiments, the step of applying the color coating in c) maybeperformed by at least one method selected from screen-coating,roll-coating, or spray-coating.

In embodiments, the step of curing the color coating in d) may beperformed by heat-curing or UV (ultraviolet light) curing.

In embodiments, the step of removing the conductive ribbon in e) mayoccur prior to the curing of the color coating in step d).

In embodiments, the ribbon may be secured in the channel by an adhesivepositioned in the channel to temporarily fix the ribbon to the holderduring the coating method provided herein. In such embodiments, theadhesive is configured to additionally remove contaminants from thebottom surface of the conductive ribbon when the conductive ribbon isseparated from the temporary hold of the adhesive thereby releasing theribbon from the channel and/or holder.

In embodiments, the ribbon may include pores, the pores may be added tothe ribbon before or after the coating methods described herein. Inembodiments, the pores may be formed by exposing the ribbons to apunching process.

In some embodiments, the methods described herein for forming a colorconductive ribbon for a solar module include: a) securing a top surfaceof a base sheet, the top surface including an adhesive material, to abottom surface of a masking sheet, b) forming a channel configured toreceive a conductive ribbon in at least the masking sheet to form aribbon holder, c) securing the conductive ribbon in the channel of theribbon holder, d) applying a color coating to at least the conductiveribbon secured within the channel, e) curing the color coating on theconductive ribbon, and f) separating the conductive ribbon from thechannel of the ribbon holder.

In still other embodiments, the methods described herein for forming acolor conductive ribbon for a solar module include the steps of: a)securing a top surface of a masking sheet, the top surface including anfirst adhesive material, to a bottom surface of a handling sheet, b)securing a top surface of a base sheet, the top surface including ansecond adhesive material, to a bottom surface of the masking sheet, c)forming a channel configured to receive a conductive ribbon in at leastthe masking sheet to form a ribbon holder, d) securing the conductiveribbon in the channel of the ribbon holder, e) applying a color coatingto at least the conductive ribbon secured within the channel, f) curingthe color coating on the conductive ribbon, and g) separating theconductive ribbon from the channel of the ribbon holder.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of the present disclosure are described hereinbelow withreference to the drawings, which are incorporated in and constitute apart of this specification, wherein:

FIGS. 1A and 1B are top views of two types of solar modules includingsolar cells with electrically conductive ribbons;

FIG. 2 depicts a flow diagram of a method of forming colored conductiveribbons as described in at least one embodiment herein;

FIG. 3A is a perspective view of a ribbon holder including at least onechannel as described in at least one embodiment herein;

FIGS. 3B and 3C are cross-sectional views of ribbon holders including aconductive ribbon secured in a channel as described in at least oneembodiment herein;

FIG. 4 is a perspective view of a ribbon holder including a conductiveribbon as described in at least one embodiment herein;

FIG. 5 is a perspective view of a ribbon holder including at least onechannel as described in at least one embodiment herein;

FIG. 6 is a perspective view of a ribbon holder including at least onechannel as described in at least one embodiment herein;

FIG. 7 is a perspective view of a ribbon holder including at least onechannel as described in at least one embodiment herein;

FIGS. 8A and 8B are schematic views of methods of forming coloredconductive ribbons as described in at least one embodiment herein;

FIGS. 9A and 9B are schematic views of methods of forming coloredconductive ribbons using the ribbon holder of FIG. 4, as described in atleast one embodiment herein;

FIGS. 10A and 10B are schematic views of methods of forming coloredconductive ribbons as described in at least one embodiment herein;

FIGS. 11A and 11B are schematic views of methods of forming coloredconductive ribbons as described in at least one embodiment herein;

FIGS. 12A and 12B are schematic cross-sectional side views of methods ofroughening conductive ribbons as described in at least one embodimentherein; and

FIGS. 13-16 are schematic cross-sectional side views of methods ofroughening conductive ribbons as described in at least one embodimentherein.

DETAILED DESCRIPTION

Further details and aspects of exemplary embodiments of the presentdisclosure are described in more detail below with reference to theappended figures.

The present disclosure is directed to methods of forming solar modulesand particularly solar modules formed from strips of solar cells thatinclude additional materials attached thereto, such as electricallyconductive ribbons, which are colored to improve the efficiency and/oraesthetics of the solar module and/or solar cell.

The solar cells of the present disclosure are used as the building blockof solar modules. A solar cell is made up of a substrate configured tobe capable of producing energy by converting light energy intoelectricity. Examples of suitable photovoltaic material include, but arenot limited to, those made from multicrystalline or monocrystallinesilicon wafers. These wafers may be processed through the major solarcell processing steps, which include wet or dry texturization, junctiondiffusion, silicate glass layer removal and edge isolation, siliconnitride anti-reflection layer coating, front and back metallization. Thewafers may be further processed through advanced solar processing steps,including adding rear passivation coating and selective patterning tothereby obtain a passivated emitter rear contact (PERC) solar cell,which has a higher efficiency than solar cells formed using the standardprocess flow mentioned above. The solar cell may be a p-typemonocrystalline cell or an n-type monocrystalline cell in otherembodiments. Similar to the diffused junction solar cells described asabove, other high efficiency solar cells, including heterojunction solarcells, can utilize the same metallization patterns in order to be usedfor the manufacture of a shingled array module. The solar cell may havea substantially square shape with chamfered corners (a pseudo-square) ora full square shape.

FIG. 1A depicts a top view of a first type of solar module 10 formedfrom strings 11 of solar cells 12, wherein the strings 11 areinterconnected electrically via conductive bus ribbons 13. In addition,the solar cells 12 are interconnected electrically via conductive tabribbons 14. The electrically conductive ribbons, such as bus ribbons 13and tab ribbons 14, are designed to carry the electric output producedby the solar cells 12 from one solar cell to another neighboring solarcell and/or from one string 11 to another neighboring string. Theelectrically conductive ribbons, such as bus ribbons 13 and tab ribbons14, can be fixed to the solar cells or solar module by any suitablemethod known to those skilled in the art, including but not limited tothe use of electrically conductive adhesives (ECAs) and/or the use ofsolders.

As further depicted in FIG. 1A, the electrically conductive tab ribbons14 are positioned across a central area of the solar cells 12 therebybeing fully visible from a top surface of the solar cell and blockingsome sunlight or shading some portion of the solar cells 12.

In FIG. 1B, a top view of a second type of solar module 19 formed froman array of shingled strips of solar cells 18 combined to form a string16, wherein the strings 16 are interconnected electrically viaconductive bus ribbons 17 a-d. In addition, the solar cells may beinterconnected electrically via conductive tab ribbons (not shown)positioned on a bottom side of solar module 19 opposite the top sidedepicted in FIG. 1B. The electrically conductive ribbons, such as busribbons 17 a-d and tab ribbons, are designed to carry the electricoutput produced by the solar cells from one solar cell to anotherneighboring solar cell and/or from one strip to another neighboringstrip and/or from one string to another string. The electricallyconductive ribbons, such as bus ribbons 17 a-d and the tab ribbons, canbe fixed to the solar cells or solar module by any suitable method knownto those skilled in the art, including but not limited to the use ofelectrically conductive adhesives (ECAs) and/or the use of solders.

Electrically conductive ribbons for solar cells or modules are commonlymade from metallic materials. Some examples of suitable metallicmaterials which efficiently conduct electricity include copper, gold,silver, tin, iron, nickel, lead, and the like. In addition, theconductive ribbons may be coated with metal alloys which will not onlyprotect the copper but also provide better bonding to the solar cells.The metal alloys include, but are not limited to, Pb/Sn, Pb/Sn/Ag,Sn/Ag, Bi/Sn/Ag, etc.

In any case, the ribbons are great for conducting electricity but aresolid pieces of metal which can shade at least a portion of the solarcell or module and further can be easily soiled with contaminants duringprocessing. Contaminants on the bottom side or inwardly facing side ofthe ribbon can decrease the surface area of the electrical contactpoints between the ribbon and the solar cell, the solar module, and/orother ribbons, thereby decreasing the efficiency of the ribbon toconduct electricity.

In addition, the ribbons are not aesthetically pleasing because theuncoated ribbons may stand out against and/or may be in stark contrastto, the black or blue background of the average solar cell or module.Thus, it would be beneficial aesthetically to be able to add a color tothe ribbons on the top side or outwardly facing side of the ribbon whileimproving efficiency of the ribbon by optimizing a contaminant freebottom side or inwardly facing side as a result of the coating process,as described herein.

As shown in FIG. 2, a colored conductive ribbon(s) can be manufacturedfrom at least the steps provided. Generally, at least one conductiveribbon is combined with a channeled ribbon holder and a color coating isapplied to at least one side of the conductive ribbon. In embodiments,the color coating is also applied to at least some portion of thechanneled ribbon holder. In embodiments, the coating is applied only tothe top side of the ribbon.

In embodiments, the color coating is applied by placing the combinedconductive ribbon and ribbon holder into a coating device, i.e., ascreen-coater, roll-coater, or spray-coater, and the color coating isscreened, sprayed, and/or rolled onto at least the top surface of theconductive ribbon. The color coating on the conductive ribbon is thencured to form a colored conductive ribbon on at least one side, i.e.,the top side facing outward from the channel, and the conductive ribbonis separated from the channeled ribbon holder. The present process isintended to leave a bottom side, i.e., the side opposite the top side,of the conductive ribbon uncoated. It is envisioned that the uncoatedbottom surface will be the surface on which the conductive ribbonsdescribed herein will be attached to the solar cells, solar modules,and/or other ribbons. In some embodiments, the color coating is curedusing a heating process. In some embodiments, the color coating is curedusing a UV process.

In some embodiments, the coating is cured and then separated from theribbon holder. For example, this may be in a reel to reel processingscenario where the ribbon is constantly fed through the ribbon holder asit is unwound from a reel of ribbon material and wound onto a new reelof coated ribbon material. In other embodiments, the ribbon may beseparated from the ribbon holder before and/or during the curingprocess.

As provided herein, a color-coating is intended to encompass acomposition including at least one color, pigment, and/or dye. It isenvisioned that any color may be used. However, some particularlyembodiments, the color-coating may be a composition which renders theconductive ribbons black, such as black paint or ink. In some otherparticular embodiments, the color-coating may be a composition whichrenders the conductive ribbons white, such as white paint or ink. Insome embodiments, the paint may be an electrically conductive paint,i.e., BARE® conductive electric paint. In embodiments, the paint may bea thermally insulative paint. In embodiments, the color coating may forma textured coating suitable for improving the amount of light reflectedfrom the ribbons back to the solar cells.

In addition to the color, pigment, and/or dye, the color coatingsdescribed herein may include various other ingredients commonlyassociated with color coatings, such as binders, extenders, solvents,volatile organic compounds, dispersants, thixotropic agents, driers,bactericides, fungicides, algaecides, fragrances, and combinationsthereof. In embodiments, the color coating is a liquid. In embodiments,the color coating is a powder.

Turning now to FIGS. 3A and 3B, the ribbon holder 22 includes at leastone channel 25 dimensioned and configured to receive the at least oneconductive ribbon 20. For example, the channel includes a channellength, channel width, and/or channel depth generally equal to theribbon length, ribbon width, and/or ribbon height of the conductiveribbon 20 thereby ensuring a suitably snug yet removable fit of theribbon 20 within the channel 25. The ribbon holder 22 includes a holderlength, holder width, and holder height, wherein at least the holderwidth and holder height of the holder 22 is greater than the ribbonwidth and ribbon height of ribbon 20.

In some embodiments, as shown in FIG. 3C, the channel depth of channel25 may be less than the ribbon height of the conductive ribbon 20, whichmay assist in limiting the application of the color coating to only theconductive ribbon 20 (and not the ribbon holder 22) because the topsurface 20 a of the conductive ribbon 20 will extend beyond the topsurface 22 a of the holder 22.

The channel 25 may include a pair of sidewalls 25 a, 25 b which definethe channel depth by extending from the top surface 22 a of the ribbonholder 22 to the bottom surface 25 c of the channel 25. As shown, thesidewalls 25 a, 25 b may be generally parallel to each other andconnected to each other via the base surface 25 c of the channel 25which may be generally perpendicular to the sidewalls 25 a, 25 b. It isenvisioned however, that in some other embodiments, the sidewalls maynot be generally parallel to each other and/or the base surface may notbe generally perpendicular thereto. Also, although depicted as generallyrectangular shapes, the ribbon holders, channels, and/or conductiveribbon may of any shape suitable for performing the methods describedherein.

As further illustrated in FIGS. 3A-3C, the base surface 25 c mayincludes an adhesive 26 for removably or temporarily securing theconductive ribbon 20, particularly the bottom surface 20 b of theconductive ribbon 20, within the channel 25 during the coating processesdescribed herein. The coating can also operate as an overspray barrierpreventing adhesion of any of the coating on the uncoated surface of theribbon. As the adhesion bond between the base surface 25 c of thechannel 25 and the bottom surface 20 b of the conductive ribbon 20 isonly intended to be temporary, the bond strength is configured to besufficient to withstand the forces applied thereto during any coatingand/or curing processes, while remaining configured to be broken byforces slightly higher than those applied during the coating and/orcuring processes, so the ribbon can eventually be removed from thechannel fairly easily. The adhesive layer may be readily removed fromthe underside of the ribbon using one or more solvents, even water, toensure a clean surface for eventual bonding with the strings 11 andelectrical conduction therethrough. Alternatively, the adhesive may beselected to have a greater adhesion to the holder than the ribbon andthus remain in place when the ribbon is removed from the holder, and thesolvents may be applied to the holder to remove the adhesive. Somenon-limiting examples of suitable adhesives include pressure sensitiveadhesives, hot-melt adhesives, dissolvable adhesives, reactiveadhesives, two-part adhesives, synthetic adhesives, bioadhesives, andcombinations thereof.

In some embodiments, the adhesive is a pressure sensitive adhesive. Somepressure sensitive adhesives may include of an elastomer, such asnatural rubber, vinyl ethers, acrylics, butyl rubber, styrene blockcopolymers, silicones and nitriles. In some embodiments, the pressuresensitive adhesive may be selected based on the adhesive's adhesionstrength over a certain period of time. For example, the pressuresensitive adhesive may be a peelable PSA wherein the adhesive isintended to be removed at some point of time without damaging the ribbonand/or the ribbon holder. Other non-limiting examples include high-tackPSAs, permanent PSAs, and/or freezer PSAs.

In addition, the adhesive 26 may prevent and/or remove possiblecontaminants from the bottom surface 20 b of the conductive ribbon 20when the ribbon is removed from the channel. For example, anycontaminants on the bottom surface of the ribbon may become secured tothe adhesive during the coating and/or curing processes described hereinand remain adhered to the adhesive when the ribbon is separated from thechannel thereby providing a top side of the ribbon which is color coatedand bottom side of the ribbon including a reduced amount of contaminantsand/or free of any contaminants.

In FIG. 4, a ribbon holder 110 is depicted including a channel 115 inreceipt of a conductive ribbon 120 and a pair of masking tabs 130 a, 130b. Masking tabs 130 a, 130 b define an opening 135 having an openingwidth less than the channel width. Such a configuration allows themasking tabs 130 a, 130 b to prevent some portions, in this instance theouter edges 123 of the top surface 122 of the conductive ribbon 120 fromreceiving any color coating during the application process. Althoughdepicted as having a generally straight edge, it is envisioned that theedges of the masking tabs 130 a, 130 b may be the same or different andmay be of any shape or configuration, i.e., rounded, sinusoidal, jagged,etc.

In some embodiments, the masking tabs may be made from the same materialused to form the ribbon holder. In some embodiments the masking tabs maybe added to the ribbon holder separately. In some embodiments, themasking tabs may be removable and/or replaceable from the ribbon holder.In some embodiments, the masking tabs may be made from a paper, rubber,silicone, or plastic material suitable for preventing the color coatingmaterial from being applied to at least a portion of the conductiveribbon.

As shown in FIGS. 3 and 4, in some embodiments, the ribbon holder can bea single layer of sheet material, i.e., a single sheet. In otherembodiments, as depicted in FIGS. 5 and 6 and described in more detailbelow, the ribbon holder can be formed of multiple layers of sheetmaterial, i.e., multiple sheets.

The ribbon holders described regardless of layers may be made from anymaterial suitable for securing the ribbon during the coating and/orcuring processes described herein. For example, in some embodiments, theribbon holder may be made from plastic or polymeric materials which canbe molded, pressed, extruded, and the like to form the overall shape ofthe holder. In some embodiments, the ribbon holder maybe made from paperand/or paper-like products such as cardboard.

In some embodiments, the channeled ribbon holder may be formed from anysuitable molding, extruding, and/or pressing process. In someembodiments, the channel of the ribbon holder of a single sheet may beformed after formation of the ribbon holder, i.e., by cutting outmaterial from the ribbon holder to form the channel.

Turning to FIG. 5, the ribbon holder 210 include at least one maskingsheet 212 positioned directly on top a base sheet 211 including and/orcoated with an adhesive 225. Ribbon holder 210 includes channel 215formed in or by the at least one masking sheet 212. For example, in someembodiments, a plurality of masking sheets may be positioned directlyupon base sheet 211 in a spaced apart configuration creating gaps orchannels between each of the masking sheets and leaving a portion of thebase sheet exposed or uncovered creating the channel therebetween. Insome other embodiments, a single masking sheet 212 may be positioneddirectly upon base sheet 211 and then the masking sheet may be cut toremove a portion of the masking sheet from the base sheet 211 therebycreating the channel 215.

In some embodiments, the ribbon holder includes one channel or at leastone channel. In other embodiments, the ribbon holder includes multiplechannels, which in turn may receive multiple conductive ribbons. Inembodiments, one channel receives one ribbon.

As shown in FIGS. 6 and 7, the ribbon holders 310, 410 may be formedfrom two or more sheets, and particularly, three sheets, i.e., basesheet 311, 411, masking sheet 312, 412, and protective sheet 313, 413.The masking sheets 312, 412 are positioned directly on top a base sheet311, 411 via an adhesive 325, 425 and form channels 315, 415 a, 415 b.The protective sheets 313, 413 are positioned directly on a top ofmasking sheets 312, 412 via adhesive 335, 435 and the protective sheets313, 413 are intended to at least prevent premature access to thechannels 315, 415 a, 415 b to the ribbons and/or contaminants.

In some embodiments, the protective sheet 313, 413 may be combined withthe masking sheet 312, 412 to predetermine the width of the channels315, 415 a, 415 b prior to be adding to the base sheet 310, 410. Theprotective sheet is typically removed from the masking sheet afterformation of the channel and prior to receipt of the conductive ribbonwithin the channel.

Turning to FIG. 8, a process is illustrated for forming a coloredconductive ribbon as described herein. Initially, a base sheet 511including a top surface coated with an adhesive is combined with amasking sheet 512, and particularly, the masking sheet 512 covers amajority, if not the entire, base sheet 511. Once combined, the maskingsheet 512 is cut to remove a portion of the masking sheet 512 therebycreating a channel 515. The masking sheet may be cut using any suitablemethod. Some non-limiting examples include cutting with a laser, aknife, a blade, ultrasonics, a press, scissors, and the like. Uponremoval of the cut piece of masking sheet 512 and the formation ofchannel 515, a conductive ribbon 520 is positioned and/or secured withinthe channel 515 and the sidewalls are formed from the remaining portionsof the masking sheet 512. In embodiments, the conductive ribbon 520 issecured in the channel 515 via the adhesive positioned on the topsurface of the base sheet 511. It is envisioned that in some instances,the adhesive may be reapplied to the base surface of the channel uponremoval of the cut piece of the masking sheet and prior to receipt ofthe ribbon, as removal of the cut piece may also remove some of theadhesive originally positioned on the base sheet.

As further shown in FIG. 8, the top surface of the conductive ribbon 520is uncolored and/or displays a metallic finish prior to coating. Next, acolor coating is applied to the conductive ribbon 520 secured in thechannel 515 of the ribbon holder 513, the color coating on theconductive ribbon 520 is cured, and the color coated conductive ribbonis separated from the channel of the ribbon holder.

In some embodiments, the color coated conductive ribbon 520 isphysically separated from the channel 515 of the ribbon holder 513 aftercuring. For example, in some instances, the cured color coatedconductive ribbon 520 can be peeled away from the channel 515, and moreparticularly peeled away from the adhesive on the top surface of thebase sheet 511. In such instances, once the ribbon is peeled away fromthe ribbon holder, no portion of the ribbon holder remains in contactwith the ribbon.

In some embodiments, the color coated conductive ribbon 520 isphysically separated from the ribbon holder 513 by cutting or punchingthe ribbon 520 free of the ribbon holder 513. When cut or punched freefrom the ribbon holder 513, at least some portion of the base sheet 511may also be cut or punched free of the ribbon holder 513 and remainadhered to ribbon 520 thereby leaving the ribbon 520 adhered to at leasta portion, if not all, of the base sheet 511.

As further depicted in FIG. 8, the colored conductive ribbon may be asolid ribbon 520 a or a ribbon including pores 520 b. It is envisionedthat the pores may be added at any time during the processes describedherein. For example, in some embodiments, the pores may be added to theconductive ribbons prior to entering the channel. In such embodiments,the color coating, when applied, may not only cover the top surface ofthe ribbon but also some portion, if not all, of the inner wall of thepore defined in the thickness of the ribbon.

In some other embodiments, the pores may be added to the conductiveribbon after the coating is applied. In still other embodiments, thepores may be added to the conductive ribbon after the curing of thecoating and/or upon separation of the ribbon from the channel. In suchembodiments, the inner walls of the pores may not include the colorcoating.

In some embodiments, the pores may be symmetrically distributed acrossthe ribbon.

In some embodiments, the pores may be non-symmetrically distributedacross the ribbon. For example, the pores may be closer to one edge ofthe ribbon than another edge of the ribbon. Due to the non-symmetricaldistribution of the pores, the surface area of the ribbon which isadhered to the base sheet 511 may not be evenly distributed. Removal ofthe adhered base sheet 511 will cause the ribbon to produce a curvedsurface because the peeling force of the base sheet 511 cannot be evenlydistributed across the ribbon due to the asymmetrical pores. Therefore,in such embodiments, it may be beneficial to remove the color coatedribbon completely from the base sheet 511 (as well as the channel orribbon holder) prior to the formation of the asymmetrical pores toprevent curving or bowing of the non-symmetrical pored ribbon.

In FIG. 8B, another process is illustrated for forming a coloredconductive ribbon as described herein. Initially, a plurality of maskingsheets 612 a, 612 b spaced apart from each other and secured to an outerprotective sheet 613 via an adhesive are combined with a base sheet 610,the masking sheets 612 a, 612 b positioned between the protective sheet613 and the base sheet 610. The protective sheet 613 temporarily coversthe masking sheets 612 a, 612 b, the base sheet 610, and the channel615. Once combined, the protective sheet 613 is removed from the maskingsheets 612 a, 612 b to provide access to the channel 615. Upon removalof the protective sheet 613, a conductive ribbon 620 is positionedand/or secured within the channel 615 via an adhesive and the sidewallsformed from the remaining portions of the masking sheets 612 a, 612 b.Next, a color coating is applied to the conductive ribbon 620 secured inthe channel 615 of the ribbon holder 614, the color coating on theconductive ribbon 620 is cured, and the color coated conductive ribbonis separated from the channel of the ribbon holder 614.

Although FIGS. 8A and 8B depict processes utilizing a multilayer ribbonholder similar to those shown in FIGS. 5 and 6, it is envisioned thatthe processes of coating a conductive ribbon described in FIGS. 8A and8B may alternatively utilize a single layer ribbon holder, such as anyof the ribbon holders shown in FIGS. 3A, 3B, 3C, 4 and/or 7.

In some embodiments, the conductive ribbons may be coated in a mannergenerally as shown in FIG. 8A or 8B wherein the ribbon holder of FIG. 4is utilized, as either a single or multilayer ribbon holder. As shown inFIGS. 9A and 9B, the conductive ribbon 650, 660 is coated utilizing theribbon holder of FIG. 4 to form a coated conductive ribbon 650 a, 660 ahaving first and second uncoated outer edge portions 653 a, 653 b, 663a, 663 b which extend longitudinally along the length of the coatedribbon 650 a, 660 a. Uncoated outer edge portions 653 a, 653 b, 663 a,663 b are positioned on either side of a coated central portion 655,665.

Uncoated outer edge portions 653 a, 653 b, 663 a, 663 b can be removedor separated from the coated central portion 655, 665 to form a coatedconductive ribbon 650 b, 670 a, 670 b, 670 c including only coatedcentral portion 655, 665. The uncoated outer edges 653 a, 653 b, 663 a,663 b can be mechanically cut or separated from coated central portion655, 665 using any suitable method, including but not limited to cuttingwith a blade, press, punch or laser.

By utilizing ribbon holders similar to FIG. 4, the outer edges of theconductive ribbon remain uncoated and prevent the coating from reachingthe rear side of conductive ribbon during the coating and/or curingprocesses. As a result, in some embodiments, the channel of theconductive ribbon of FIG. 4 may not include an adhesive and/or the rearside of the conductive ribbon of FIGS. 9A and 9B may not be attached toan adhesive or tape during the coating process.

As further depicted in FIGS. 8A, 8B, 9A, and 9B, the colored conductiveribbons may be a solid (free of pores) ribbon 520 a, 620 a, 670 a, 670b, 670 c, 655 or a ribbon including pores 520 b, 620 b, 650 b, 675 a,675 b, 675 c. It is envisioned that the pores may be added to the ribbonat any time during the processes described herein. For example, in someembodiments as shown in FIGS. 10A and 10B, the pores may be added to theconductive ribbons prior to entering the channel and/or prior to theapplication of the color coating. In such embodiments, the coatingcomposition when applied may not only cover the top surface of theribbon but also some portion, if not all, of the inner wall of the poredefined in the thickness of the ribbon.

In some other embodiments, as shown in FIGS. 9A, 9B, 11A and 11B, thepores may be added to the conductive ribbon after the color coating isapplied and/or cured. In still other embodiments, the pores may be addedto the conductive ribbon after the curing of the coating and/or uponseparation of the ribbon from the channel. In such embodiments, theinner walls of the pores may not include the color coating.

As shown in FIGS. 9A, 9B, and 10A, in some embodiments, an electricallyconductive ribbon 655, 665, 710 free of pores (solid) may be processedin some manner to include pores. In embodiments, the pores are formedvia a punching process. The process of punching or removal of someportion of the conductive ribbon to form the pores can be performed inseveral ways, such as a mechanical punching processes or laserablation/cutting processes. In particular embodiments, the pores may becreated with a punch. Once punched (pores formed), the punchedconductive ribbon may be coated via one of the processes describedherein. As specifically shown in FIGS. 9A, 9B, and 10A, the punchedconductive ribbons may be coated with a color coating, i.e., a blackpaint or composition, and cured to produce a colored and/or blackconductive ribbon.

In some embodiments, as shown in FIGS. 9B and 10B, the conductive ribbonthat is processed may have a sufficient width that following the coatingprocesses described herein, the colored conductive ribbon can be thensliced into a plurality of thinner strips having a smaller widthsuitable as either a tabbing ribbon or bus ribbon.

As further depicted in FIG. 10B, an extra wide electrically conductiveribbon 810 free of pores (solid) may be processed in some manner toinclude pores. In embodiments, the pores are formed via a punchingprocess. The process of punching or removal of the some portion of theconductive ribbon to form the pores can be performed in several ways,such as a mechanical punching processes or a laser ablation processes.In particular embodiments, the pores may be created with a punch. Oncepunched (pores formed), the punched conductive ribbon 820 may be coatedvia one of the processes described herein with a color coating. Asspecifically shown in FIG. 10B, the punched conductive ribbon 820 may becoated with a color coating, i.e., a black paint or composition, andcured to produce a colored and/or black conductive ribbon 830. Thecolored and/or black conductive ribbon may then be sliced into aplurality of thinner strips having a smaller width 840 a-d. The step ofslicing may be performed using a plurality of lasers, knives, blades,ultrasonics, presses, scissors, and combinations thereof.

As shown in FIG. 11A, in some embodiments, an electrically conductiveribbon 910 free of pores (solid) may be coated via one of the processesdescribed herein with a color coating. Once coated and/or cured, thecolor coated conductive ribbon may be processed in some manner toinclude pores. In embodiments, the pores are formed via a punchingprocess. The process of punching or removal of the some portion of thecoated conductive ribbon to form the pores can be performed in severalways, such as a mechanical punching processes or a laser ablationprocesses. In particular embodiments, the pores may be created with apunch.

As specifically shown in FIG. 11A, the conductive ribbon 910 may becoated with a color coating, i.e., a black paint or composition, andcured to produce a colored and/or black conductive ribbon 920, which cansubsequently be punched to form pores within the coated conductiveribbon forming a color coated porous conductive ribbon and/or a blackcoated porous conductive ribbon 930.

In some embodiments, as shown in FIG. 11B, the conductive ribbon 950that is processed may have a sufficient width that following the coatingprocesses described herein, the colored conductive ribbon 950 can bethen sliced into a plurality of thinner strips having a smaller widthsuitable as either a tabbing ribbon or bus ribbon.

As further depicted in FIG. 11B, an extra wide electrically conductiveribbon 950 free of pores (solid) may be coated with a color coating,i.e., a black paint or composition, and cured to produce a coloredand/or black conductive ribbon 960. In some embodiments, the coloredand/or black conductive ribbon 960 may be processed in some manner toinclude pores. In embodiments, the pores are formed via a punchingprocess. The process of punching or removal of the some portion of theconductive ribbon to form the pores can be performed in several ways,such as a mechanical punching processes or a laser ablation processes.In particular embodiments, the pores may be created with a punch. Oncepunched (pores formed), the punched colored conductive ribbon 970 may besliced into a plurality of thinner strips having a smaller width 980a-d. The step of slicing may be performed using a plurality of lasers,knives, blades, ultrasonics, presses, scissors, and combinations thereofcoated via one of the processes described herein with a color coating.

In alternative embodiments, the colored and/or black conductive ribbon960 may be sliced into a plurality of thinner strips having a smallerwidth 975 a-d prior to being made to include pores, i.e., punched. Oncesliced into thinner strips, the plurality of strips may be collectivelyor individually processed to include pores, i.e., punched, to formpunched strips of colored conductive ribbons 980 e-h.

In still other embodiments, as depicted in FIGS. 12A-16, the conductiveribbons described herein may be roughened, at anytime during themanufacturing process, to add a textured surface to at least a portionof the ribbon surface. By adding a textured surface to the ribbon, thebond strength or peeling strength of the ribbon is greatly improved whenadhered or bonded to a solar cell (including solar strips or solarmodules) along the textured portion of the ribbon.

In some embodiments, the ribbons may be roughened to include a texturedsurface prior to coating. In some embodiments, the ribbons may beroughened to include a textured surface after coating.

The textured surface may be continuous or discontinuous along any outersurface of the ribbon. In some embodiments, the textured surface is onlyon portions of the outer surface of the ribbon which are not coated. Insome embodiments, the textured surface is only on coated portions of theouter surface of the ribbon. In some embodiments, the textured surfaceis on coated portions and non-coated portions of the outer surface ofthe ribbon.

As depicted in FIG. 12A, in some embodiments, the conductive ribbon 1210can be passed between at least one roughening element 1220 and agenerally flat hard surface 1230 to produce a textured surface 1240 a-con at least one surface of the conductive ribbon 1210. As furtherdepicted in FIG. 12A, the roughening element 1220 is a roller whichrotates as indicated by the arrow forcing outer surface 1221 of theroller 1220 against a first surface 1210 b of ribbon 1210 to roughen thesurface creating a texture. Specifically, the conductive ribbon 1210,either coated or uncoated, may initially have a smooth non-texturedsurface 1210 a prior to passing by the roughening element 1220. Theroughening element 1220 having an outer surface 1221 configured toroughen smooth surface 1220 a against hard surface 1230 to produce atextured surface 1240 a-c on at least a first side 1210 b of ribbon1210. The texture of the textured surface may be random (surface 1240 a)or patterned (surface 1240 b, 1240 c) of various depths. The rougheningelement 1220 may include an outer surface 1221 including a patternedcoarseness which when applied to the ribbon 1210, under the correctconditions, i.e., pressure, temperature, length of time, etc., transfersthe mirror image of the patterned coarseness to at least a first side1210 b of ribbon 1210. Although illustrated as a process performed in asingle pass and in a single direction, it is envisioned that any of theroughening processes described herein may include multiple passes of theribbon over the roughening element and/or in any number of directions.

As depicted in FIG. 12B, in some embodiments, the conductive ribbon 1210can be passed between a plurality of roughening elements 1220, 1222 toproduce a textured surface 1245 a-c on at least two surfaces of theconductive ribbon 1210. The two surfaces being opposite each other, suchas a top and bottom surface. Roughening elements 1220, 1222 are depictedas rollers which rotate as indicated by the respective arrows forcingouter surfaces 1221, 1223 of the rollers 1220, 1222 against a firstsmooth surface 1210 b and a second smooth surface 1215 b of ribbon 1210to roughen the ribbon on multiple surfaces creating a texture thereon.Specifically, the conductive ribbon 1210, either coated or uncoated, mayinitially have a generally smooth non-textured surface 1210 a, 1215 aprior to passing by the roughening element 1220, 1222 to produce adual-sided textured ribbon including first textured surface 1210 b andsecond textured surface 1215 b.

As depicted in FIG. 13, in some embodiments, the conductive ribbon 1310can be passed between a press 1330 and at least one roughening element1320, such as a textured linear surface, to produce a textured surface1340 a-c on at least one surface of the conductive ribbon 1310. In suchembodiments, the textured linear surface of roughening element 1320 maybe stationary while the press 1330 is configured to move or slide (asindicated by the arrow) towards the roughening element 1320 while theribbon 1310 is positioned therebetween. It is envisioned that in someembodiments, the press may also a textured surface configured to roughena second surface opposite the first surface. In addition, in someembodiments, both the press and the roughening element are configured tomove or slide towards each other with the ribbon positionedtherebetween.

As depicted in FIG. 14, in some embodiments, the conductive ribbon 1410can be ground over a textured linear roughening element 1420, such as anemery board, emery stone or grinding tool, to produce a textured surface1440 a-b on at least one surface of the conductive ribbon 1410. In suchembodiments, at least one of the roughening element 1420 or ribbon 1410are moved relative to the other under pressure to roughen the surface ofthe ribbon 1410.

Turning to FIG. 15, in some embodiments, the roughening element 1520 isa laser device configured to laser scan or carve the textured surface1540 a-c onto at least one side 1510 a of the conductive ribbon 1510. Insome embodiments, the laser device 1520 is movable in any direction,i.e., forward, back, up, down, side-to-side, etc., relative to theribbon 1510 which may be stationary. Although depicted on only one sideof the ribbon, it is envisioned that laser device may be positioned onmultiple sides of the ribbon.

In FIG. 16, the roughing element 1620 does not roughen the surface ofribbon 1610 by removing material. Rather, roughening element 1620 isconfigured to add material, such as particles or sand, to the surface ofthe ribbon 1610 to create a textured surface 1640 a-c. In someembodiments, the roughening element 1620 is a sand blaster capable ofmoving in any direction, i.e., forward, back, up, down, side-to-side,etc., relative to the ribbon 1610 which may be stationary. Althoughdepicted on only one side of the ribbon, it is envisioned that the sandblaster may be positioned on multiple sides of the ribbon.

The textured surfaces as described herein can create a roughnesscreating grooves, channels, dimples, crevices, etc. having a depthranging from 0.01 microns to 1000 microns. In some embodiments, thedepth of the roughness may range from about 0.1 microns to 500 microns.In some embodiments, the depth of the roughness may range from about 1micron to 250 microns. In some embodiments, the depth of the roughnessmay range from about 10 microns to 100 microns.

The textured surface as described herein can improve the bondingstrength or peeling strength between the coated ribbon and the solarcell by a range of 0.1N to 1N. In some embodiments, by a range of 0.2Nto 0.5N. In some embodiments, by a range from 0.3N to 0.4N.

In some embodiments, the present disclosure describes a solar moduleincluding a plurality of strings of solar cells, each string includingan array of shingled strips of solar cells, and at least oneelectrically conductive bus ribbon connected to the plurality ofstrings, wherein the at least one electrically conductive bus ribbonincludes a color coating on at least a first outer surface of the busribbon. The electrically conductive ribbon may soldered to the stringsof the solar module and/or may be adhered to the strings of the solarmodule using known electrically conductive adhesives. In someembodiments, the color coating is on top surface of the ribbon. In someembodiments, the color coating is both the top and opposite bottomsurfaces of the ribbon.

In some embodiments, the color coating on the ribbon is a blackcomposition. In some embodiments, the black composition is a blackpaint. In some embodiments, the black paint is an electricallyconductive black paint.

In some embodiments, the color coating is on a central portion of theelectrically conductive ribbon, the central portion extendinglongitudinally along a length of the electrically conductive ribbon withuncoated first and second outer edges extending longitudinally along thelength of the electrically conductive ribbon and positioned on eitherside the central portion.

In some embodiments, at least a second outer surface opposite the firstouter surface is free of contaminants after the first surface is coloredwith the color coating composition.

In some embodiments, the electrically conductive ribbon further includesa plurality of pores.

In some embodiments, the plurality of pores are asymmetricallydistributed across the ribbon.

In some embodiments, at least a second outer surface opposite the firstouter surface includes a textured surface.

In some embodiments, the textured surface includes a roughness having adepth from about 0.01 to about 1000 microns.

In some embodiments, the textured surface increases the bonding strengthbetween the electrically conductive ribbon and the string of solar cellsof from about 0.3N to 0.4N.

In addition to electrically conductive materials, some additionalmaterials which may be frequently attached to the top surfaces of asolar cell or module include for example identification labels. Althoughnot necessarily electrically conductive, identification labels, such asbar codes or QR codes, are often applied to each of the individual solarcells or solar modules to ensure the authenticity of the source of thesolar cells or modules. However, these labels are often predominantlywhite which, like metallic conductive ribbons, can not only stand outaesthetically when placed on a black solar cell or module, but furthermay provide small areas of shading on the cells or modules.

Accordingly, it would be beneficial both aesthetically andefficiency-wise to provide identification labels which are predominantlynot white. For example, in embodiments, the labels may be colored, suchas black or blue, to match the solar cell or module and the bar code orQR code information may be printed using a different color coatingcomposition, i.e., ink. For example, in particular embodiments, a blacklabel may be processed as described herein to be coated with a white inkwherein the white ink represents the bar code information and the blacklabel is the background. In such embodiments, the black and whiteportions of the usual bar code or QR code are reversed rendering most ofthe label black and a minority of the label white, thereby allowing amajority of the label to blend with the solar cell or module surface.

Another option to obtaining the same label effect may include startingwith the normal white labels and applying a black coating as describedherein. However, instead of printing the bar code or QR code informationin black, the coating may be applied to form an outline or stencil ofthe bar code or QR code information, i.e., reverse print the codeinformation. In such embodiments, the white label would show through theblack outlined coating as the bar code or QR code information. In suchembodiments, the black and white portions of the usual bar code or QRcode are reversed rendering most of the label black and a minority ofthe label white, thereby allowing a majority of the label to blend withthe solar cell or module surface.

While several embodiments of the disclosure have been shown in thedrawings, it is not intended that the disclosure be limited thereto, asit is intended that the disclosure be as broad in scope as the art willallow and that the specification be read likewise. Any combination ofthe above embodiments is also envisioned and is within the scope of theappended claims. Therefore, the above description should not beconstrued as limiting, but merely as exemplifications of particularembodiments. Those skilled in the art will envision other modificationswithin the scope of the claims appended hereto.

What is claimed is:
 1. A method comprising: providing a ribbon holderconfigured to receive a conductive ribbon for a solar module;temporarily securing the conductive ribbon in the ribbon holder;applying a color coating to the conductive ribbon; curing the colorcoating on the conductive ribbon; and separating the conductive ribbonfrom the ribbon holder.
 2. The method of claim 1 wherein the conductiveribbon is temporarily secured in the ribbon holder with adhesive.
 3. Themethod of claim 2, wherein the adhesive comprises one or more of ahot-melt adhesive, a dissolvable adhesive, a reactive adhesive, atwo-part adhesive, a synthetic adhesive, and a bioadhesive.
 4. Themethod of claim 2, wherein the adhesive material includes a pressuresensitive adhesive comprising at least one of an elastomer, a naturalrubber, a vinyl ether, an acrylic, a butyl rubber, a styrene blockcopolymer, a silicone, and a nitrile.
 5. The method of claim 1, whereinthe separating comprises at least one of peeling, punching, cutting, andusing a solvent.
 6. The method of claim 1, wherein the ribbon holderincludes a single layer of sheet material.
 7. The method of claim 1,wherein the ribbon holder includes multiple layers including at least abase sheet including a top surface including the adhesive material and amasking sheet including a bottom surface secured the top surface of thebase sheet by the adhesive material.
 8. The method of claim 7, whereinthe multiple layers of the ribbon holder further includes a protectivesheet removably attached on a top surface of the masking sheet.
 9. Themethod of claim 7, wherein the conductive ribbon is secured within achannel of the ribbon holder.
 10. The method of claim 9, wherein thechannel is formed by removing material.
 11. The method of claim 9,wherein the channel is formed by at least one of molding, extruding, andpressing.
 12. The method of claim 1, wherein the adhesive removescontaminants from a bottom surface of the conductive ribbon whenseparating the conductive ribbon from the channel.
 13. The method ofclaim 1, wherein applying the color coating includes at least one ofscreen-coating, roll-coating, or spray-coating.
 14. The method of claim1, wherein curing the color coating of includes heat-curing or UVcuring.
 15. The method of claim 1, wherein separating the conductiveribbon occurs prior to curing the color coating.
 16. The method of claim1, further comprising slicing the conductive ribbon into thinner stripsafter removing the conductive ribbon from the channel.
 17. The method ofclaim 1, further comprising imparting a textured surface to theconductive ribbon by at least one of roughening and adding material. 18.The method of claim 1, wherein the color coating is a black composition.19. The method of claim 1, wherein the color coating is an electricallyconductive paint.
 20. The method of claim 1, wherein the color coatingis a powder.